- Gay te tiem ngam: la tiern thuoc gay te VaG dudi da d~ thuoc tham VaG than kinh Phuong phap nay thuong dung khi nh6 rang, trich mun nhot,
3. THUnC GAy TE co cAu TRUC AMID 1 Lidocain(Xylocain, Lignocain)
3.1. Lidocain (Xylocain, Lignocain)
Duac d9ng hoc
Lidocain hap thu duoc qua duong tieu hoa nhung bi chuyen hoa qua gan lftn dftu IOn.'I'iem gay gian mach noi tiem, vi vay neudung gay te thi thuong phoi hop vdi chat co mach d~ giam hap thu thuoc, Vao mau, thuoc lien ke't vdi protein huyet tuong khoang 70%. Thu6c co ai luc cao vdi t6 chuc hon vdi huyet tuong, d(lcbiet la ph6i, nao sau do de'n tim, gan, lach, ruot, co va m6 rna. Thu6c qua nhau thai khoang 40%. Thu6c chuyen hoa d gan khoang 70% bang phan ung alkyl hoa va hydroxyl hoa tao ra 2 chat chuyen hoa quan trong Ia monoethylglycinxylidin (MEGX)va glycinxylidin (GX)v§.ncon hoat tinh chong loan nhip tim. Thai trir chu yeuqua nude ti~u dudi dang da chuyen hoa,
Tcic dung
- Gay te: lidocain vita co tac dung gay te bg mat do thu6c tham t6t qua niem m?c vita co tac d\mg gay te bg sau (gay te d§.ntruygn, gay te tiem tham). Tac d\lng cua lidocain m?nh hdn procain khoang 4 lftn va d9Chdn. Tac d\lng xuat hi~n nhanh va keo dai hdn. Vi thu6c gay gian m?ch ndi tiem nen thudng phai ph6i hQp voi cac chat gay co m?ch nhu noradrenalin, adrenalin d ty l~ 1180.000 hoiftc11 100.000 d~ keo dai tac d\lng gay te va giam tac d\lng kh6ng mong muon cua thuoc.
- Tren thftn kinh v?n d9ng va thftn kinh thl;iCV?t: tac d\lng tudng tl;i procam.
- Ch6ng lo?n nhip: gi6ng quinidin, thu6c co tac d\lng 6n dinh mang te' bao lam giam tinh tl;i dQngva rut ngl1nthdi ky trd cua tim. Khac quinidin la lidocain kh6ng anh hUdng Wi d~n truygn nQit?i cua cd tim, it anh hUdng Wi suc co bop cua cdtim va m?ch ngo?i vi.
- Cd che':xem phftn d?icudng thu6c gay teo
Chi dinh
- Gay te: gay te niem m?c, gay te tiem tham va gay te d§.ntruygn.
- Ch6ng lo?n nhip tim: lo?n nhip do ngQ dQcdigitalis, lo?n nhip that do huye't kh6icdtim, lo?n nhip do thu5c gay me va ngo?i tam thu.
Tcic d,!ng khfmg mong muon
- Dung gay te (t?i ch6): co th~ g(lp viem tl1cHnh m?ch, viem mang nh~n, shock phan v~.
- Dung chong lo?n nhip (toan than): co th~ giftpchong miftt,bu6n ngu, hi l§.n, ch~m nhip tim, h? huyet ap, co gi?t.
- Qua ligu gay tr\lY tim m?ch, rung tam that, roi lo?n nhip hoiftcngitng tim, ngiing h6 hap, co th~ gay ti't vong.
Ch{ing chi dinh
- M~n cam vdi lidocain.
- HQichimg Adams - Stokes, rol1o~ xoang-nhinang, blocnhithat, suy tim nang. - Benh nhuoc co.
- Roi loan chuc nang gan.
Tuangtac thuoc
Lidocain va cac thuoc gay te cau true amid chuyen hoa d gan, nen cac thuoc lic che' enzym gan nhu thuoc khang histamin H2 (cimetidin) lam tang tac dung va keo dai tac dung cua lidocain va cac thuoc gay te cung loai.
Dung d5ng thoi thuoc uc che'p- adrenergic (propranolol) vdi lidocain co th~ lam cham chuyen hoa lidocain do lam giam luu luong mau tdi gan d~n de'n tang nguy co ngQ dQclidocain.